Load detecting devices, for example transducers or extensometers, are mounted to a structure, for example a rear axle of a mobile crane, to measure a force applied to the structure by converting the force into an electrical output signal. Such load detecting devices can detect when a set of wheels connected to the rear axle of the crane or other support member is at risk of lifting off the ground, causing a hazardous situation.
Prior art load detecting devices typically comprise a carrier unit mounted to the structure and which carrier unit carries a plurality of strain gages (or “gauges”). As the carrier unit is deformed under tensile and compressive forces from a force applied to the structure, an electrical resistance of each strain gage (or “gauge”) changes and the changes can be measured, for example, in a full bridge circuit with four active arms. Conventional load detecting devices often suffer from weak output signals and a non-linear relationship between a change in applied force and a change in the output voltage. Such disadvantages reduce the sensitivity and accuracy of the load detection.